The fragments, released by the Vatican in 1972, were a gift to the Holy Family Church from the Shrine of Our Lady of Pompeii, also in Chicago. Displaying them now has particular significance because of their association with Christmas, which marks the birth of Jesus.
The Rev. Jeremiah J. Boland, administrator of the church, said on Friday that he is "not that interested" in carbon testing the items to see if they are from the beginning of the Christian Era.
"The Vatican has its own process to determine the authenticity of things," Boland said. "I'm more concerned with it as an object of faith."